This invention relates generally to microfluidics, and more specifically to transfer of liquid samples from a set of wells to a substrate surface.
Small sample volumes are desired in many research and development applications directed to identifying new disease markers and bringing to the clinic new diagnostic assays and therapeutic drugs. In order to reap the benefits of sensitive assay systems and to avoid the need for harvesting large biological samples, procedures required to prepare and assay the samples need to be capable of transferring and manipulating small volumes of fluid. In particular, microarray-based technologies are useful for screening a sample against thousands of diagnostic probes or drug candidates. Thus, microarray technology can be used to effectively fractionate a single sample into thousands of assays. Again, transfer and manipulation of small volumes of sample and reagents is desired in order to take full advantage of the sensitivity and throughput of microarray-based systems.
A standard format for preparing, manipulating and storing collections of synthetic and biological molecules is that of a microplate. Microplates contain multiple wells in a plate having a standard size and shape footprint. Accordingly, many robotic systems have been designed specifically for manipulating microplates and the samples they contain. While microplates are useful for several assays, many diagnostic and research applications utilize array formats that differ from microplate formats or that require samples to be aliquoted from a single plate to multiple other formats. Although a variety of automated methods are available for sample transfer, these systems tend to be costly and mechanically complex. The equipment is typically large and, therefore, not conducive to assay miniaturization.
Thus, there exists a need for apparatus and methods to efficiently transfer and reformat liquid samples from microplates to substrate surfaces used in array methodologies. The present invention satisfies this need and provides other advantages as well.